(SportsNetwork.com) - The New York Yankees began a nine-game road trip with a victory, but little has gone right for the club since.

Now the Yankees will conclude the rough trek without one of their top hitters in Wednesday's finale of a two-game set with the Washington Nationals.

New York failed to hold an early four-run lead and lost Tuesday's opener 8-6 in 10 innings after Washington's Ryan Zimmerman hit a two-run walk-off homer. That dropped the Yankees to 2-6 on their road trip and that wasn't even the worst news.

That came after the game when the Yankees placed outfielder and leadoff hitter Jacoby Ellsbury on the 15-day disabled list due to a knee injury suffered in the fourth inning. He appeared to hurt his knee while swinging at a pitch in the frame, eventually working a walk and scoring a run.

However, Ellsbury did not come out to play defense in the bottom of the frame, replaced by Carlos Beltran in the lineup. Beltran took over in right field, with Chris Young shifting over to center.

Ellsbury had been a key to New York's early-season success, as his .324 average and 29 runs scored lead the team and the 31-year-old entered Tuesday's game tied for second in the majors with 14 stolen bases.

The Yankees are expected to purchase the contract of outfielder Slade Heathcott from Triple-A Scranton/Wilkes Barre to fill the available roster spot. Heathcott, New York's first-round pick in the 2009 MLB Draft, is hitting .285 with one home run and 17 RBI in 37 games for the RailRiders this season.

Zimmerman's heroics lifted the Nationals to a fourth straight victory as they battled back from a 6-2 deficit to win for the 16th time in 20 games.

Zimmerman followed a walk to Yunel Escobar with an opposite-field drive off Andrew Miller that struck the foul pole in right field. The blast was Washington's fourth homer of the night.

The two runs were the first Miller has permitted in 18 1/3 innings of work this season.

"Just a bad pitch," said Miller. "I can't do that there. I have to execute a better pitch in that situation."

Wilson Ramos tied the game with a solo shot in the sixth that extended his career-best hitting streak to 19 games. Ian Desmond and Bryce Harper also went deep for Washington, with Desmond finishing 2-for-5 with two RBI.

Zimmerman, meanwhile, hit the 10th walk-off homer of his career.

"We knew," Zimmerman said, "we were going to play baseball like we were supposed to."

Mark Teixeira and Stephen Drew each had two hits and a pair of RBI for the Yankees, with Teixeira delivering his 12th home run of the year.

Jordan Zimmermann aims to keep up his solid performance this month tonight for the Nationals.

Zimmermann closed out April 2-2 with a 4.88 earned run average, but has pitched to a 1.89 ERA in three starts in May while winning his lone decision. That victory came last time out on Friday against the San Diego Padres, a 10-0 decision in which the righty allowed six hits while fanning six over six innings.

"It's huge any time you get support early," Zimmermann said. "You can settle in and just throw strikes."

Zimmermann, who turns 29 on Saturday, will face the Yankees for the second time in his career. He got a no-decision in the first meeting, charged with three runs -- two earned -- over six frames.

Coming off just his second loss of the season, Adam Warren gets the call on the mound tonight for the Yankees.

Warren logged a season-high seven innings on Wednesday in a 3-2 setback to the hosting Tampa Bay Rays. He gave up three runs on seven hits and one walk, striking out seven to set another season high. Still, it resulted in his first loss since his season debut on April 11 and Warren is 2-2 on the year with a 4.50 ERA.

The right-hander has never before faced the Nationals.

The Yankees swept a three-game set in Washington when the clubs last met from June 15-17, 2012.